1. Field of the Invention
The invention relates generally to liquid level control valves. In a more particular sense, the invention is especially adapted for use as a valve that controls the inflow of water within a toilet flush tank, to replace the quantity of water flushed from the tank during normal use of the toilet facility.
The invention has particular reference to those toilet flush tank control valves wherein a float is coaxial with an upstanding fill tube, being mounted for vertical motion thereon responsive to the rise and fall of the liquid level within the flush tank.
2. Description of the Prior Art
Heretofore, float-controlled inflow valves for toilet flush tanks, having floats concentric with the upstanding, fixedly mounted fill tube, are well known per se. These, however, have had certain deficiencies in respect to smooth and efficient operation.
Problems noted in connection with devices of this type include, for example, the tendency on the part of the valve to be clogged or otherwise affected adversely by the presence of particles within the liquid. These particles tend to lodge in the valve seat, or otherwise restrict the flow of liquid through the valve, so that there is a pronounced tendency toward clogging of the valve to such an extent as would tend to prevent it from fully closing, with an attendant waste of water.
It has further been noted in prior art devices of the same general type that a maximum usage of water pressures present during the refilling operation has not been incorporated in the construction. It is desirable to take full advantage of such pressures, to render the valve operation more efficient, and to assure to the maximum extent that there will be long, trouble-free operation during the normal life of the valve assembly.